Magnetically latched relay



Aug. 3l, 1965 T. N. SAATY MAGNETICALLY LATCHED RELAY Filed Nov. l5, 1962FIG. 2

FIG. 5

INVENTOR. THEODORE N. SAATY ATTORNEYS FIG. 5

United States Patent C Jersey Filed Nov. 15, 1962, Ser. No. 237,864 12Claims. (Cl. 200--87) This invention relates to a novel electrical relayin which provision is made for producing a bagnetic field which servesto actuate the relay and for bringing into operation another magneticfield which serves to lock the relay in its actuated condition.

More specifically, the relay of the present invention includesmagnetically actuated contacts, an electrical coil or solenoid foractuating said contacts, and means for producing another magnetic fieldwhich is capable of being brought into operative relationship with thecontacts, either by the magnetic `field of the solenoid with actuatesthe contacts or by a separate solenoid, in order to hold the contacts ofthe relay in their actuated condition.

yAlthough the relay of the present'invention can be designed to bringthe latching magnetic field into or out of operation each time thesolenoid is energized, an ancillary feature of the relay is that it canalso be designed so that only the contacts of the relay will be actuatedwhen the solenoid is energized by a weaker current and the latchingmagnetic field of the relay is brought into or out of operativerelationship with the contacts only when the solenoid is energized by astronger current.

In a preferred embodiment, the latching magnetic field is produced by apermanent magnet accommodated for movement within the relay from aninoperative position to a position at which its field exerts a latchingeffect on the conta-ots of the relay. In this arrangement, both thecontacts of the relay and the permanent magnet are within and inuencedby the magnetic field produced by the solenoid. Thus, the contacts ofthe relay are actuated upon each encrgization of the solenoid, and whenthe magnetic field `of the solenoid is strong enough and of properpolarity, the permanent magnet is displaced thereby from one position toanother.

Fora more complete understanding of the invention, reference may be hadto the following detailed description taken in conjunction with theaccompanying figures of'the drawings, in which:

FIGURE 1 is a side view in longitudinal cross-section ofthe magneticallylatched relay showing the solenoid thereof energized by an electricalpotential of one polarity;

FIGURE 2 is a side view in longitudinal cross-section of the relayshown'in FIGURE 1 with the electrical potential which energizes thesolenoid reversed;

FIGURE 3 is a cross-sectional view of the relay taken along the line 3-3of FIGURE 2, looking in the direction of the arrows;

FIGURE 4 is a cross-sectional view of the relay taken along the line 4-4of FIGURE 3, looking in the direct tion `of the arrows; and

FIGURE 5 is a side view in longitudinal cross-section of anotherembodiment of the invention.

The magnetically latched relay 10, shown in FIGURE l, includes a hollowspool-like frame 11 of magnetically impermeably, rigid material, such`as Bakelite, The frame 11 has a shank 15 on which a core 14 of magnetwire is'wound between two discs 12 and 13 which form the ends of theframe 11. The shank 15 is provided with `a longitudinal channel 16extending therethrough Iand in communication with centrally disposedapertures 17 and 18 formed in the discs 12 and 13, respectively.

CTI

3,204,059 Patented Aug. 31, 1965 A switch 19, comprising a sealedcapsule 20 of glass or some similar material and containing twopartially overlapping contacts 21 and 22, formed of ferrous or othermagnetic material, is accommodated within the channel 16. The sealedcapsule 20 can, if necessary, be resiliently mounted within the channelby one or more rings or sleeves interposed between the capsule and theframe 11. The contacts 21 and 22 are embedded in and supported atopposite ends of the glass capsule, and the inner overlapping endsthereof yare normally spaced apart from each other when the coil 14 isnot energized. The external leads 21 and 22 of the contacts 21 and 22,respectively, project through and extend beyond the `apertures 17 v"and1-8, respectively.

The shank 15 of the frame 11 also ycontains a channel or groove 23 whichextends from the inner surface of the disc 13 to some distance beyondthe midsection of the frame 11. In the embodiment shown, the channel 23is in open communication with the channel 16and the outer surface of theglass capsule 20 defines part of the channel 23.

A permanent magnet 24 is accommodated within the channel 23 for slidingmovement from one end to the other. A leaf spring 2S of wavy form isaffixed to a side of the magnet 24 and bears against the Wall of thechannel 23 with light friction so that the magnet 24 will be displacedby the magnetic field established by the coil 14 but will not move orslide laccident-ally under the iniiuence of gravity if it is oriented indifferent positions.

In operation, the energization of the coil 14 produces a magnetic fieldthrough the channel 16 of the frame, closing the ferrous contacts 21 and22. In addition, if the strength of the `magnetic field is sufficient-lyhigh and of proper polarity, the permanent magnet 24 will be displacedfrom one end of the channel 23 to the other.

When the permanent magnet 24 is in the position illustrated in FIGURE 1,that is to say, the position remote from the overlapping ends of thecontacts 21 and 22, its magnetic field will not have any significanteffect on the cont-acts. When an electrical potential of proper polarityis supplied to the input terminals a, b of the coil 14, the permanentmagnet 24 will be displaced within the channel 23 from the inoperativeposition shown in FIGURE l to the operative position shown in FIGURE 2,at which operative position the magnetic field produced by the permanentmagnet will hold the contacts 21, 22 closed even though the coil 14 isthen deenergized. When the polarity of the electrical potential suppliedto the input terminals a, b of the coil 14 is reversed, as illustratedin FIGURE 2, the permanent magnet 24 will be displaced from `theoperative position shown in FIGURE 2 to the inoperative position shownin FIG- URE l.

In the operation of the relay, the energization of the coil 14,irrespective of the polarity of the electrical potenial supplied to theinput terminals a, b of the coil 14, produces a magnetic field throughthe channel 16 of the frame with maximum concentration through theferrous contacts 21 and 22, thereby closing the contacts. In addition,if the strength of the magnetic field is sufficiently high and of properpolarity, the permanent magnet 24 will be shifted between itsinoperative position `and its latching position.

In one proposed type of relay of the present invention, the coil 14 ofthe relay is responsive both to stronger and weaker pulses of varyingpolarity. The weaker pulses, irrespective of polarity, will close thecontacts 21 and 22 of the relay for the duration of the energization ofthe coil 14. On the other hand, a stronger pulse of proper polarity willdisplace the permanent magnet 24 from the inoperative position shown inPTGURE 1 to the latching position shown in FIGURE 2 to maintain thecontacts closed even beyond the duration of the pulse supplied to thecoil 14. The magnetically latched contacts 21 and 22 wili remain closeduntil a relatively strong pulse of opposite polarity is supplied to thecoil 14 to displace the permanent magnet from the latching position tothe inoperative position, whereupon after the duration of the pulse, theinherent resiliency of the contacts will restore them to open condition.

In the alternative embodiment of the invention shown in FIGURE 5, asecond coil 26 is wound on an extended end portion of the shankseparated from the coil 14 by a separator disc 27 of insulatingmaterial. The groove 23 continues into the extended portion of the shank15, terminating at the inner surface of the disc 13. A permanent magnet28 is slidingly positioned within the groove 23.

ln operation, the coil 14 is energized to close the contacts 21 and 22.Moreover, the coil Z6 is independently Ienergized by impressing anelectrical potential of proper polarity across the coil terminals c, d,where its magnetic field latches the contacts 21 and 22 in closedcondition. By reversing the polarity of the potential impressed on thecoil terminals, the magnet can be restored to its initial inoperativeposition.

Thus in the embodiment of the invention shown in FIGURE 5, the permanentmagnet is kept substantially out of the magnetic iield of the coil 14 inits inoperative position, lthereby reducing the demagnetizing influenceof the magnetic iield established by the coil 14. Moreover, the motionof the permanent magnet 28 can be controlled independently of themagnetic field of coil 14, so that only the power necessary to actuatethe contacts 21, 22 need be supplied to the coil 14.

It will be obvious to those skilled in the art that the above describedexemplary embodiments are susceptible of modification and variationWithout departing from the spirit of the invention. The invention,therefore, should not be limited to any specified form or embodiment,except insofar as such limitations are expressly set forth in theclaims.

I claim:

1. A relay comprising at least one magnetic reed contact, means forproducing a magnetic iield which, when rendered operative, latches saidcontact in one condition of operation, and means for producing areed-actuating magnetic field which is magnetically coupled with saidcontact and said lirst-mentioned means for producing a latching magneticiield said reed-actuating magnetic eld actuating the magnetic reedcontact and rendering operative the means for producing said latchingmagnetic field.

2. A relay comprising a pair of magnetically activated contacts normallyin one position relative to each other in the presence of a magneticiield, means for producing a iirst magnetic field magnetically coupledto the pair of contacts for shifting the contacts from one position toanother, means for producing a second magnetic field which means isWithin the iniluence of said first magnetic field so that if the tirstmagnetic ield is of sutiicient strength and proper polarity the meansfor producing said second magnetic eld is displaced to a position wherethe second magnetic tield holds the contacts in their actuated position.

3. A relay comprising at least one magnetic reed contact, means forproducing a rst magnetic tield which actuates the contact, and movablemeans for producing a second magnetic tield which holds the Contact inactuated condition, the movement of said movable means being determinedby the polarity of said first magnetic field.

4. A relay comprising a frame, magnetic reed contacts supported by saidframe, a Winding on said frame which,

when energized, actuates the contacts, and magnetic eld producing meanssupported for movement in said frame from a position at which themagnetic field has no influence on said contacts to a position at whichthe magnetic field holds said contacts in actuated condition, saidmovable means being displaced by the magnetic field of said Winding.

5. A relay comprising a spool-like insulated frame, a Winding on saidframe, a scaled capsule mounted Within said frame, a pair of magneticcontacts within the capsule and actuated by the energization of thewinding, and a permanent magnet within said insulated frame andaccommodated for movement from a position in which the magnetic iieldthereof has no significant iniiuence on the contacts to a position inwhich it holds the contacts in actuated condition, the displacement ofsaid permanent magnet being controlled by the magnetic field produced bysaid Winding.

6. A relay as set forth in claim 5 including resilient means to holdsaid permanent magnet against displacement by gravity.

'7. A relay comprising a frame, magnetic reed contacts, a solenoid foractuating said contacts, a magnet accommodated for movement Within saidframe from a position in which it does not hold the contacts in actuatedcondition to a position in which it holds the contacts in actuatedcondition and means for displacing the magy net from one position to theother.

8. A relay as set forth in claim 7 in which said means for displacingthe magnet is a separate solenoid.

9. A relay comprising a spool-like insulated frame, first and secondwindings on said frame, a sealed capsule within said lirst Winding,magnetically actuated contacts Within the capsule and actuated by saidiirst winding, and a magnet within said insulated frame and displaced bysaid second winding to a position in which it holds the contacts inactuated condition.

10. A relay comprising at least one magnetic reed contact, magneticmeans movable in response to a magnetic lield of sufficient strength andgiven polarity from a position at which it does not intiuence thecontact to a position at which it does iniluence the contact, andelectromagnetic means energizable to actuate the contact and, when themagnetic field produced by the electromagnetic means is of suflicientstrength and of proper polarity, to impart motion to the magnetic meansto move it from one position to another.

11. A relay comprising a frame, at least one magnetic reed contact, aguide passage for a permanent magnet, the permanent magnet at one end ofthe guide passage holding the contact closed, and at the other endpermitting vit to open, and electromagnetic means on each energizationactuating the contact and, When of predetermined polarity, impartinglatching movement to the permanent magnet.

12. A relay as set forth in claim 11 in which separate electromagneticmeans actuate the contact and impart movement to the permanent magnet.

References Cited by the Examiner UNITED STATES PATENTS 3,009,998 11/61Pfleiderer 200--87l 3,040,146 6/62` Immel et al. 200-98 3,046,370 7/62Adams et al. 200--87 OTHER REFERENCES Nitsch: (German application)1,125,055, dated March 8, 1962, KL21c68/01.

Schonerneyer et al.: (German application) 1,134,147, dated August 2,1962, KL21c68/01.

BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

1. A RELAY COMPRISING AT LEAST ONE MAGNETIC REED CONTACT, MEANS FORPRODUCTION A MAGNETIC FIELD WHICH, WHEN RENDERED OPERATIVE, LATCHES SAIDCONTACT IN ONE CONDITION OF OPERATION, AND MEANS FOR PRODUCING AREAD-ACTUATING MAGNETIC FIELD WHICH IS MAGNETICALLY COUPLED WITH SAIDCONTACT AND SAID FIRST-MENTIONED MEANS FOR PRODUCING A LATCHING MAGNETICFLELD SAID REED-ACTUATING MAGNETIC FIELD ACTUATING THE MAGNETIC REEDCONTACT AND RENDERING OPERATIVE THE MEANS FOR PRODUCING SAID LATCHINGMAGNETIC FIELD.